What does Sam and Eric's description of the beast tell us about human psychology?

Their imaginations get away from them. All they really see is the silhouette of the dead pilot in the parachute yet they describe him as, "it is furry, it has eyes, teeth, claws, wings and it chased them". This description cements the fear within the boys of the beast as a real physical manifestation of their fears. Sam an Eric are children and children are filled with imagination. Their fears are embellished with horror especially because they are already without parents and scared on this island.